Galcanezumab in patients with episodic migraine: results from the open-label period of the phase 3 PERSIST study

BACKGROUND: The phase 3 randomized PERSIST study demonstrated the efficacy and tolerability of galcanezumab, a humanized anti-calcitonin gene-related peptide (CGRP) monoclonal antibody for prevention of episodic migraines. We present findings from the open-label extension (OLE) of PERSIST, which evaluated the long-term efficacy and safety of galcanezumab in patients from China, India, and Russia. METHODS: Patients completing the 3-month double-blind period of PERSIST were eligible for the 3-month OLE. Patients previously randomized to galcanezumab (GMB/GMB group) continued to receive galcanezumab 120 mg at all three visits during the OLE whereas patients randomized to placebo received a 240 mg loading dose of galcanezumab and then two 120 mg doses (PBO/GMB group). The primary outcome was the mean change (from double-blind baseline) in the number of monthly migraine headache days (MHDs) to month 6. Other endpoints included percent reduction in monthly MHDs from double-blind baseline to month 6, functional outcomes, safety and tolerability. RESULTS: Overall, 99% of patients completing the double-blind period entered the OLE, and 96% completed through month 6. Patients in the GMB/GMB group achieved continued improvements in efficacy, with the reduction from baseline in the mean number of monthly MHDs, and slightly increasing from 4.01 days at the end of the double-blind period to 4.62 at the end of the OLE. Of patients who were ≥ 50% responders to galcanezumab at month 3, 66% maintained this response through to month 6. Patients in the PBO/GMB group experienced a rapid reduction in the number of monthly MHDs after initiation of galcanezumab, with a mean reduction from baseline of 4.56 days by month 6. The long-term benefits of galcanezumab were also supported by improvements in other efficacy and functional endpoints. All safety findings were consistent with the known long-term safety profile of galcanezumab; no patients experienced a treatment-related serious adverse event. CONCLUSIONS: Galcanezumab was efficacious and well-tolerated in patients with episodic migraine from China, India and Russia, for up to 6 months. TRIAL REGISTRATION: ClinicalTrisABSTRACT_pals.gov NCT03963232, registered May 24, 2019. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s10194-023-01613-1.